A fire at Iran’s main nuclear fuel enrichment site caused significant damage, setting back the country’s nuclear program by months, the government acknowledged on Sunday, after initially saying the destruction was minor.

A Middle Eastern intelligence official with knowledge of the episode said Israel was responsible for the attack on the Natanz nuclear complex on Thursday, using a powerful bomb. A member of the Islamic Revolutionary Guards Corps who was briefed on the matter also said an explosive was used…

If the damage at Natanz was an attack by a foreign power, it reinforces Iran’s vulnerability as its economy is strangled by sanctions imposed by a hostile Trump administration and its population is ravaged by the Covid-19 pandemic.

Tehran is increasingly isolated internationally; even countries that have opposed U.S. action against Iran recently joined in accusing it of hiding nuclear activity from international inspectors.